MAP28: The Absolution is the last level of Doom 64. The background music is the same heard in level 11, Terror Core. The layout is simple: You start off in a room containing all the weapons but the Chainsaw, including the Unmaker and a large amount of ammunition.

Leaving the room (the door cannot be re-opened after leaving), you will enter a courtyard with a pillar-like object in the center and 3 small "rooms" which cannot be entered and have a switch each next to them. The focus of the map: survive an onslaught of enemies, and then fight the Motherdemon. The key strategy will depend on whether or not you got the Demon Keys. The three unique switches are positioned north, east, and west of your position of entry to the courtyard.

Map of MAP28

The only way to activate the switches is with the keys (you do not lose them from your inventory). The more you have, the better your survival, since they close the doors of the demons' entry points.

Closing them all will greatly reduce the number of demons you have to fight, and killing what few scragglers remain will lower the center pillar, revealing a soulsphere that respawns indefinitely. The soulsphere also occasionally switches to megaarmor. The Motherdemon follows shortly after the pillar lowers. The only cover from her attacks are the pillar with the soulsphere and the "rooms" in which the hordes of enemies spawned from.

If you had the three keys, this level shouldn't be too difficult. Grab the Invulnerability upgrade, head into the arena, and close off the teleports before too many monsters arrive. Use the rocket launcher to destroy any enemies that might have spawned into the arena. Once all enemies are dead, the Motherdemon will present herself from the center pillars.

To kill the Motherdemon, use the fully-powered Unmaker or the BFG9000. The boss should be killed easily provided you have both weapons in your arsenal. The rocket launcher is also an effective weapon against her if you ran out of ammunition for the two aforementioned weapons, but be prepared for a far more difficult battle.